1. Field of the Invention
The invention pertains to a biopsy device for taking of tissues samples, which consists of a hand piece, in which a hollow biopsy needle is inserted, wherein a portion of the biopsy needle protruding from the hand piece is introduced with its sampling chamber into the tissue being investigated and the tissue is sucked into the sampling chamber by vacuum and then separated by a sample separating mechanism and finally removed.
2. Description of the Related Art
A method and a device for cutting out tissue is already known from British Patent Publication No. GB 2018601A, in which the tissue in the biopsy needle is sucked into a cutting region under vacuum influence. In order to create a vacuum in the hollow needle, the hand piece in which the hollow needle is integrated is connected via lines to a vacuum generator situated outside of the hand piece. The cutting off of the sample is done via a cutting mechanism, which is arranged lengthwise-moveable in the hollow needle. The sample cut off is kept in the needle. After pulling the needle out from the tissue, the cut-off sample is flushed out from the tip of the needle; therefore, the hand piece is connected via other lines to devices situated outside the hand piece. The vacuum established in the hollow needle is regulated by control elements integrated in the lines.
Another biopsy mechanism is known from European Patent Publication No. EP 0890 339 A1, in which the sample is removed under vacuum influence. In the hand piece, in which the biopsy needle with cutting mechanism is integrated and inserted, the biopsy needle is connected via hose connections and lines to an external vacuum generator as well as control devices. The vacuum is brought up from below to the sample removing chamber via a channel molded onto the outer sheath of the biopsy needle. The separating device is arranged lengthwise moveable in the hollow space of the biopsy needle. By a rotary movement, combined with a manual lengthwise push, the separating device cuts the sample from the tissue. The sample is transported in the hollow channel of the separating device. A similar arrangement is also shown by U.S. Pat. No. 5,526,822, and here in particular various vacuum feed lines to the sample removal chamber are known, such as the arrangement for cutting mechanisms, in the hollow needle or coaxially as a cutting sheath, on the outside. In both biopsy mechanisms capable of removal of a sample under vacuum, the hand piece of the biopsy device is limited in its freedom of motion by at least one connection hose and/or supply cables to one or more external supply units; furthermore, the mechanisms for creating the vacuum are costly, especially in regard to the regulating mechanisms. The sample is cut out by rotating separation devices which can move lengthwise in the hollow needle chamber.
Furthermore, a suction biopsy device is known from German Patent No. DE 40 41 614 C1, which is fashioned as a manual device and which has a partial vacuum source as well as a biopsy cannula connection, which can be placed in rotation by a flexible shaft located outside the hand piece. A biopsy cannula fashioned as a hollow cannula can be mounted on the biopsy cannula connection, preferably having a revolving cutting edge sharpened at the distal end, along whose hollow channel a partial vacuum can be applied, by means of the partial vacuum source, which is configured as a piston and cylinder unit, once the hollow cannula has been positioned at a particular tissue point inside the body. A similar partial vacuum-assisted biopsy device can be found in International Publication No. WO 96/28097, which, though not specifying any hollow cannula placed in rotation, nevertheless has a syringe plunger arrangement located inside a manual device to create partial vacuum.
German Patent Publication No. DE 100 34 297 A1 describes, in contrast with the above suction biopsy arrangement with only a single hollow needle, a tissue removal endoscopy instrument, having a biopsy needle arrangement, which specifies a circumferentially sharpened hollow needle at its distal end and a hollow biopsy needle guided inside the hollow needle, wherein the internally guided biopsy needle has a recess for removal of a tissue sample at its distal end. Proximal to the hollow biopsy needle is a suctioning instrument for creating a partial vacuum. A removal of tissue occurs in that the biopsy needle arrangement is pushed in a joint position into a region of tissue being investigated, while the biopsy needle has a distal tip, which protrudes distally from the hollow needle for a length in order to facilitate the process of penetration of the biopsy needle arrangement into the tissue, on the one hand, and to prevent tissue from getting into the interior of the hollow needle, on the other hand. When the biopsy needle arrangement is suitably positioned inside the tissue, the hollow needle is pulled back proximally for a particular length, while the interior biopsy cannula remains in position and the recess is made free. The partial vacuum applied along the biopsy needle produces an active lowering or drawing of surrounding tissue parts into the recess. By controlled distal pushing of the hollow needle with its sharpened distal end beyond the biopsy needle, a portion of the tissue is separated and enclosed inside the recess of the biopsy needle. Then, by joint withdrawal of the biopsy needle arrangement, the separated tissue sample is removed from the body for examination purposes. The entire tissue removal process described above occurs in such a way that the needle movements and the application of partial vacuum are performed manually, individually and separated from each other. With German Patent Publication No. DE 100 34 297 A1, which is considered to be the closest state of the art, the vacuum biopsy device for removal of tissue is based on the problem of configuring the hand piece so that the sample removal sequence can be operated with one hand after being inserted by means of a coaxial cannula, or with no such cannula.
On the other hand, the biopsy needle arrangement described in International Publication No. WO 98/25522 enables a spring-operated relative motion between the hollow biopsy needle, located on the interior, and the outer hollow needle surrounding the biopsy needle. In this case as well, the biopsy needle is positioned distally to the sharpened distal tip of the hollow needle in order to take a sample, there being provided a partial vacuum source for supplying a partial vacuum through the hollow biopsy needle into the area of its recess, assisting the process of bringing in the tissue. The process of positioning the biopsy needle relatively and finally inside the region of tissue being investigated is done exclusively manually. Such a positioning leads only to unsatisfactory biopsy results, especially when investigating hard tissue regions.
Likewise, a vacuum-assisted biopsy device is described in US Patent Publication No. 2001/0011156 A1, which calls for a compactly configured hand device, in whose housing all drive elements necessary for propelling the needle of the biopsy needle arrangement are provided. However, a partial vacuum source is provided separate from the hand device, which can be connected via an appropriate supply line to the needle arrangement inside the hand device at a suitable connection location.